Differential drive mechanism for tentering machine



March 4, 1969 I J. M. RICHBOURG 3,430,310

v DIFFERENTIAL DRIVE MECHANISM FOR TENTERING MACHINE Filed Feb. 8, 1967 Sheet of 4 29 Q ATTORNEY HA vE R 6 8i 1 13A JA :ES ;?RlCHBOURG 82 BY 83 80 27A aims mailm- March 4, 1969 RlCHBCURG 3,430,310

DIFFERENTIAL DRIVE MECHANISM FOR TENTERING MACHINE Filed Feb. 8, 1967 Sheet 3 of 4 INVENTOR JAMES M. RICHBOURG ATTQRNEY March 4, 1969 J. M. RICHBOURG 3,430,310

DIFFERENTIAL DRIVE MECHANISM FOR TENTERING MACHINE Filed Feb. 8, 1967 35 6 i. a :52 m m 63 I I: f I '1 H l lll'l hll l'hll l l'M'l l!I UI K UM UUUM l P P H. 30 29 l 51v 52 ALA 127 FIG IO INVENTOR JAMES M. RICHBOURG ATTORNEY United States Patent 6 Claims ABSTRACT OF THE DISCLOSURE Differential drive mechanism to provide different relative speeds on oppositely located rotating mechanisms.

This invention relates to a differential drive for a tentering machine and more particularly for correcting the skew at the material entering end of a tenter or for controlling the relative speeds of oppositely located endless chains thru drive sprockets.

An object of the present invention is to provide a differential drive which can be used to control the relative speed between two endless chains in a tentering machine through control of the drive sprockets or to control the overfeed mechanism in a tenten'ng machine.

Another object of the present invention is to provide a differential drive, whereby improved means are used to provide weft correction.

Still another object of the present invention is to provide an improved differential drive in a tentering machine to maintain absolute equal and parallel selvage speed through a tenter after weft alignment has been accomplished.

And still another object of the present invention is to provide a skew correction rate commensurate with the mean rate of speed of the material traveling through the tenter. At slow travel speeds a slow correction rate is employed. At higher travel speeds a higher correction rate is employed.

Other objects of the present invention will become apparent in part and be pointed out in part in the following specification and claims.

Like reference characters refer to like parts in the following drawings, in which:

FIGURE 1 is a fragmentary perspective view, of the material entering end of a tentering machine.

FIGURE 2 is a plan view of FIGURE 1.

FIGURE 3 is a view similar to FIGURE 2, but of the opposite end of the tentering machine.

FIGURE 4 is an end elevational view of FIGURE 3 with brackets broken away and with the chain driving elements in cross section.

FIGURE 5 is a horizontal cross-sectional view through the differential drive mechanism, taken on line 5-5 of FIGURE 1.

FIGURE 6 is a vertical cross-sectional view taken on line 66 of FIGURE 3.

FIGURE 7 is a fragmentary perspective view partly in section, of the connection between the frame and the differential drive mechanism.

FIGURE 8 is a fragmentary perspective view, partly in section, of a guide rail, saddle and frame member.

FIGURE 9 is a fragmentary vertical cross-sectional view, of the mechanism for adjusting the guide rail.

FIGURE 10 is a fragmentary plan view, partly in section, of the overfeed mechanism.

In proceeding with this invention, a differential drive, shown in FIGURE 5, is adapted to control an overfeed device, shown in FIGURES l and 2, whereby, material is piled upon pin clips in a manner to straighten the 3,430,310 Patented Mar. 4, 1969 weft of the material in correcting a skew condition in the material. Similarly, in FIGURES 3 and 4, the differential drive is adapted to control the endless tenter clip chain on one side of the tenter in relation to the endless tenter clip chain on the opposite side of the tenter.

The tentering machine or tenter comprises conventional pairs of guide rails 11, 11A, 12, 12A provided, respectively, with rail faces 13, 13A, 14, 14A. Top cases 15, 15A, 16, 16A are fastened, respectively, to side rails 11, 11A, 12, 12A. Endless tenter clip chains 17, 18 ride or travel in side rails 11, 11A and 12, 12A, respectively, while engaging rail faces 13, 13A and 14, 14A, respectively, and are held in position by means of top cases 15, 15A and 16, 16A, respectively, which engage the tail sections 17A, 18A, respectively, of tenter clips 19, 20 constituting the tenter clip endless chains 17, 18, respectively. Pin clips are illustrated in FIG- URES 1 and 2 by way of example and not by Way of limitation.

Idler sprockets 23 and 24, engage, respectively, endless tenter clip chains 17 and 18 at the material entering end of the tenter (see FIGS. 1 and 2) and drive sprockets 25, 26 engage, respectively, endless tenter clip chains 17, 18 on the delivery end of the tenter.

In practice a tenter comprises a plurality of cross members 27 fastened on opposite ends to stanchions 27A, 27B which support the cross members 27 above the floor. Each cross member 27 is finished to provide a track having a top 30 and opposite sides; one side being indicated at 31. A shaft 29, provided with left hand threads 32 and right hand threads 33 is rotatively supported in bearings 34 fastened to a top 30 of cross member 27. A saddle 35 is provided for each left hand thread 32 and a saddle 35A is provided for each right hand thread 33. Saddle 35 is slidably mounted upon cross member 27 and specifically upon top 30 and opposite sides 31, 31A. A handle 37 is fastened to one end of each shaft 29 for the manual rotation thereof.

With reference to FIGURE 8, saddles 35, 35A are provided with sliding faces 40, 41 and sliding ends 42, 43 to slidingly engage, respectively, top 30 and sides 31A, 31.

The construction of saddle 35 will be described. It will be understood that the plurality of saddles are identically constructed.

Reference is now made to FIGURE 9. Saddle 3 5 is provided with a chamber 60. A nut 61 provided with a screw thread of a hand adapted to rotatively engage left hand thread 32 is located in chamber and is held therein by means of ribs 62, 63.

Rotation of hand wheel 37 causes nut 61 to engage either rib 62 or "63 to slide saddle 35 upon cross member 27 toward or away from hearing 34.

With reference to FIGURES 8 and 9, saddle 35 is provided with a longitudinal groove 51. A block 52 is slidably mounted in longitudinal groove 51. A pivot pin 53 is fastened in block 52. Rails 11, 11A provided with an integrally formed bracket 11B are provided with an orifice 11C to accommodate pivot pin 53. In this manner rails 11, 11A are pivotally mounted upon saddles 35, whereby rotation of hand wheel 37 and shaft 29 moves saddles 35, 35A toward and away from each other through left hand thread 32 and right hand thread 33, respectively, and thereby rails 11, 11A and 12, 12A are moved toward and away from each other, in the manner and purposes known to the tenter frame art.

An overfeed mechanism is generally indicated by reference numeral 75. A platform 76 is fastened to top case 15 by means of block 77 and to top case 15A by means of block 78. Two pillow blocks 80, 81 are fastened to platform 76. A shaft '82 having pulleys 83, 84 fastened thereto, is rotatively mounted in pillow blocks 80, 81.

Three additional pillow blocks 85, 86 and 79 are fastened to platform 76. A shaft 89 having pulley 87 fastened thereon, is rotatively mounted in pillow blocks '85, 86. A belt 88 rotatively connects pulley 87 with pulley 84. A spur gear 90 is fastened to shaft 89. A bracket 91 is fastened to platform 76. A lever 92 having brush wheel 93 rotatively mounted on one end, is pivotally connected to bracket 91 at 94.

overfeed mechanism 75 is well known to the art. It is illustrated herein, by way of example to show one type of mechanism which can be controlled by the differential drive mechanism illustrated in FIGURES 1, 2 and 5.

Overfeed mechanism 75 consists of a cylinder 95 fastened to a circular flange 300 by means of screw threads. 301. Flange 300 is provided with a cavity 302 and is rotatively mounted upon a spur gear 97 fastened to flange 330 by means of key 312. Spur gear 97 meshes with spur gear 90. Shaft 96 is supported in bearing 79. A disc 303 is provided with a chamber 304 and a plurality of orifices 305. A cam 306 is located in chamber 304 and with disc 30-3 is rotatively mounted upon shaft 96. A plurality of pins 307 are located in orifices 305 and rest against cam 306. A plurality of bristles 310 forming a brush are fastened in flange 300 and surround pins 307 which move into and out of bristles 310 under the influence of cam 306 as cylinder 95 rotates. Pins 307 and bristles 310 coact with pin clips 19, on one side of the tenter frame to lay the material on the pin clips. Pins 307 and bristles 310 overlie the material while the pin clips 19 are beneath the material.

Pins 307 and bristles 310 also co-act with pin clips 20 in like manner on the opposite side of the tenter frame.

Reference is now made to FIGURES 1 and 5 wherein is illustrated a differential drive consisting of a drive shaft 100. Two pillow blocks102 and 103 are fastened to a bracket 104 attached to side 31 of the machine frame. Similarly, two pillow blocks (not shown) are fastened to a bracket (not shown) attached to side 31 at the opposite side of the machine frame, Drive shaft is rotatively mounted in pillow block 102 and in the counterpart pillow block 102A located on the opposite side of the machine frame. (See FIGURE 5.)

A pillow block 105 is fastened to a bracket 104 attached to side 31. A first driven shaft 101 is rotatively mounted in pillow blocks 103, 105. Similarly, a pillow block 107 is fastened to a bracket 108 attached to side 31. A second driven shaft 110 is rotatively mounted in pillow block 107 and in a counterpart 111 to pillow block 103 located isn the opposite side of the machine frame. (See FIGURE The various pulleys will be described in a manner to prevent confusion when referred to in the claims.

Motor driven pulley 112, first pulley 113 and fifth pulley 116 are fastened to shaft 100 by means of keys 114, 115, and 118, respectively. Sixth pulley 117 is freely rotatable upon shaft 100. An overrunning air clutch generally indicated at is provided with a hub 126 keyed at 127 to shaft 100 and a second pulley 128 is freely rotatable upon shaft 100. A friction plate 130 is interposed between hub 1 26 and second pulley 128 so that when air pressure actuates the mechanism in hub 126 friction plate 130 will connect hub 126 to second pulley 128, thereby rotating second pulley 128 with the drive shaft 100.

A third pulley 132 is fastened to first driven shaft 101 by means of a key 133'. A belt 134 connects third pulley 132 with second pulley 128.

An overriding cam clutch generally indicated at 135 consists of a hub 145 fastened to first driven shaft 101 by means of key 148. An overriding clutch element 150 is provided with a fourth pulley 146. A belt 147 connects fourth pulley 146 to first pulley 113. Rotation of drive shaft 100 rotates first pulley 113 and through belt 147 and fourth pulley 146 and clutch element 150, hub 145 is rotated, thereby rotating first driven shaft 101. Should first driven shaft 101 be rotating at a faster r.p.m. than 4 hub 145, then the overriding clutch 150 will become operative and hub 145 will rotate at a faster r.p.m., than if hub 145 was driven by fourth pulley 146. Slippage takes place in clutch element 150.

A tenth pulley 136 is fastened to first driven shaft 101 by means of key 137.

A motor (not shown) has a drive pulley 140 fastened to the end of the motor shaft 141. A belt 142 connects drive pulley 140 with motor driven pulley 112, whereby drive shaft 100 is rotated. First pulley 113 through belt connection 147 rotates fourth pulley 146, and thereby first driven shaft 101 as previously stated. First driven shaft 101 rotates tenth pulley 136 and through belt 152 ninth pulley 83 is rotated whereby shaft 82, transfer pulley 84, belt 88, first overfeed drive pulley 87, gear 86, gear 90 and overfeed wheel 95 is rotated. Overfeed wheel 95 places the cloth upon the pin clips 17.

Similarly, drive shaft 100 rotates fifth pulley 116, belt 147A, eighth pulley 146A, hub 145A, second driven shaft 110, thirteenth pulley 136A, belt 152A and the overfeed mechanism on the opposite side of the tenter frame at 75A. 1

In theory, overfeed mechanism 75, 75A should uniformly place opposite sides of a web of material upon pin clips 17, 18 with opposite edges parallel. Too, frequently cloth bunches up or skews, whereby the web of cloth has one edge carried by one set of pin clips behind the opposite edge of cloth carried by the opposite set of pin clips.

In that event, the operative presses a button which allows air to actuate air clutch 125 or 125A.

Fourth pulley 146 has a ratio of 3 to 1 in relation to first pulley 113. Third pulley 132 has a ratio of 2 to l in relation to second pulley 128. Therefore, when air clutch 125 is actuated so that second pulley 128 is rotated through friction plate 130, drive shaft 100 will rotate first driven shaft 101 faster through belt 134 and third pulley 132 than the normal rotation of first driven shaft 101 through first pulley 113 and fourth pulley 146 and clutch element 150 with hub 148.

First driven shaft 101 therefore, by way of example, will rotate faster than second driven shaft 110 whereby overfeed mechanism 75 will rotate faster than overfeed mechanism 75A. Thus, the cloth will be placed upon the pin clips 17 faster than the cloth is placed upon the pin clips 18. In this way the web of material is controlled in placing opposite sides of the material upon the pin clips 17, 18 of a tentering machine.

Attention is now directed to FIGURES 3, 4, 5 and 6 of the drawings, wherein is illustrated the cloth exit end of the tentering machine. Stanchions 200, 201 and 202 support cross members 203 and 204. In FIGURE 4, the cross member 204 is broken away and the several parts are shown in cross-section in the interest of clarity. A gear housing 212 provided with gibs 217 and 218 is fastened, respectively, to cross members 204 and 203. A stub shaft 213 (FIG. 6) provided with a bevel gear 214 fastened to one end is rotatively mounted in gear housing 212 with a sprocket hub 220 provided with a sprocket 25, fastened on the other end. A bottom gear case 210 is fastened to gear housing 212 at flanges 221. Side rail 11 provided with top case 15 is supported upon gear housing 212 (see FIG. 6). Bottom gear case 212 is provided with a bearing 223 which rotatively supports stub shaft 213. Endless tenter clip chain 17 rotatively engages sprocket 25. Gear housing 212 is provided with two opening which are closed, respectively, by means of end caps 211 and 224 (FIG. 4).

The sprocket 26 (FIG. 3) is constructed in an identical manner to sprocket 25. The corresponding parts relating to sprocket 26 will have the suffix A added thereto.

The differential drive illustrated in FIGURE 5 is adaptable to drive sprockets 25, 26 at relative speeds to each other. Only the pillow blocks recited in relation to FIG- URES l, 2 and 5 will be changed to bearing supports with reference to FIGURES 3, 4, 6.

Drive shaft 100 is rotatively supported in bearings 102A fastened to stanchion 202 and bearing 99A fastened to stanchion 200. First driven shaft 101 is rotatively supported on one end in stanchion 200 and on the other end in stanchion 202. First driven shaft 101 has a gear 215 fixed thereto and is rotatively supported in end caps 211 and 224. Gear 215 meshes with gear 214.

In like manner second driven shaft 110 is rotatively supported on one end in stanchion 2G1 and on the other end in stanchion 202. Second driven shaft 110 has a gear 215A fixed thereto and is rotatively supported in end caps 211A and 224A. Gear 215A meshes with gear 214A.

In the absence of overfeed mechanism 75 and 75A, the new and improved differential drive illustrated in FIG- URE 5 may be used to straighten the weft through control of the relative movement of sprocket in relation to sprocket 26.

The differential drive mechanism shown in FIGURES 3 and 4 is the same as the differential drive mechanism shown in FIGURE 5. The same reference numerals are used. However, the Sllfi'lX A or AA has been added to distinguish between the use of the differential drive mechanism used to control overfeed mechanism and the use of the differential drive mechanism to control sprockets 25, 26.

Reference is made to FIGURES 3 and 4 for an operative description thereof:

The motor rotates motor shaft 141A and motor pulley 148A and through belt 142AA motor driven pulley 112A rotates drive shaft 100. First pulley 113AA through belt 147AA rotates fourth pulley 146AA and overriding clutch element 150 (FIGURE 5) which rotates hub 145 keyed at 148 to first driven shaft 101.

Hub 126AA as an element of overrunning air clutch AA is keyed as at 127 (FIG. 5) to drive shaft 1G0.

Second pulley 128AA is freely rotatable upon drive shaft 100. A friction plate 130AA is interposed between hub 126AA and second pulley 128AA so that when air pressure actuates the mechanism in hub 126AA friction plate 130AA will connect hub 126AA to second pulley 128AA, to rotate second pulley 128AA with drive shaft 100. Belt 134AA connects second pulley 128AA with third pulley 132AA fastened to first driven shaft 101 as by means of key 133 (FIG. 5) to thereby rotate first driven shaft 101.

Should third pulley 132AA rotate first driven shaft 101 faster than fourth pulley 146AA then overriding clutch 150AA will become operative and hub AA will rotate faster than if hub 145AA was driven by fourth pulley 146AA. Slippage takes place in clutch element ISOAA.

First driven shaft 101 through gear 215 rotates gear 214, stub shaft 213, hub 220 and sprocket 25.

In like manner, fifth pulley 116A through belt 147AAA rotates eighth pulley 146AAA and overriding clutch element 150AAA which rotates hub 145AAA keyed to seeond driven shaft 110.

As previously described for first driven shaft 101, second driven shaft 110 (FIGURE 4) will rotate gears 215A and 214A whereby stub shaft 213A, hub 220A and sprocket 26 will be rotated.

Through control of friction plates 130 and 130A first driven shaft 101 and second driven shaft 110, respectively, will drive sprockets 25, 26 respectively, relative to each other.

Reference is made to FIGURE 7 wherein is illustrated a plug 350 provided with a stem 351 and slidably mounted upon shaft 101 by means of a key 137. Tenth pulley 136 is rotatably mounted, in this modified form of construction, upon a flange fixed to plug 359. Saddle 35 is provided with means to slidably accommodate a slide bar 354 attached to stem 351.

In operation, saddle 35 is moved as previously explained. Plug 350 and pulley 136 will move along first driven shaft 101 to maintain belt 152 in alignment between tenth pulley 136 and pulley 80.

Having shown and described preferred embodiments of the present invention by way of example, it should be realized that structural changes could be made and other examples given without departing from either the spirit or scope of this invention.

What I claim is:

1. A differential drive consisting of a drive shaft and a first driven shaft, means on said drive shaft for rotating said drive shaft, a first pulley fixed to said drive shaft, an overriding air clutch having a hub fixed to said drive shaft, a second pulley freely rotatable upon said drive shaft and a friction element between said hub and second pulley, means actuating said air clutch, whereby said fric tion element unites said second pulley with said hub to rotate said second pulley, said first driven shaft having a third pulley fixed thereon, drive means between said second pulley and said third pulley, an overriding cam clutch having a hub fastened to said first driven shaft, an overriding clutch element provided with a fourth pulley rotatively mounted upon said hub, drive means between said first pulley and said fourth pulley whereby said drive shaft rotates said fourth pulley, said hub and said first driven shaft, said overriding cam clutch being operative upon actuation of said friction element whereby said third pulley rotates said first driven shaft faster than the rotation imparted by said fourth pulley, a fifth pulley fixed to said drive shaft and an overriding air clutch having a hub fixed to said drive shaft, a sixth pulley freely rotatable upon said drive shaft and a friction element between said hub and sixth pulley, means actuating said air clutch whereby said friction element unites said sixth pulley with said hub to rotate said sixth pulley, a second driven shaft having a seventh pulley fixed thereon, drive means between said seventh pulley and said sixth pulley, an overriding cam clutch having a hub fastened to said second driven shaft, an overriding clutch element provided with an eighth pulley rotatively mounted upon said hub, drive means between said eighth pulley and said fifth pulley whereby said drive shaft rotates said eighth pulley, said hub and said second driven shaft, said overriding cam clutch being operative upon actuation of said friction element whereby said seventh pulley rotates said second driven shaft faster than the rotation imparted by said eighth pulley, a machine frame, said drive shaft, said first driven shaft and said second driven shaft being rotatably mounted in said machine frame, a first pair of side rails, a second pair of side rails, means slidably mounting said first pair of said rails and said second pair of side rails on said machine frame for movement toward and away from each other, a first platform fixed to said first pair of side rails, a second platform fixed to said second pair of side rails, a ninth pulley, means rotatably mounting said ninth pulley to said first platform, a tenth pulley fastened to said first driven shaft, drive means connecting said ninth pulley to said tenth pulley, a first overfeed device, means rotatively supporting said first overfeed device on said first platform, said first overfeed device including a first overfeed drive pulley, drive means connecting said ninth pulley to said first overfeed drive pulley, a second overfeed device, means rotatively supporting said second overfeed device on said second platform, said second overfeed device including a second overfeed drive pulley, an eleventh pulley, means rotatably mounting said eleventh pulley to said second platform, a twelfth pulley fastened to said second driven shaft, drive means connecting said twelfth pulley to said eleventh pulley to rotate said second overfeed device.

2. A differential drive consisting of a drive shaft and a first driven shaft, means on said drive shaft for rotating said drive shaft, a first pulley fixed to said drive shaft, an overriding air clutch having a hub fixed to said drive shaft, a second pulley freely rotatable upon said drive shaft and a friction element between said hub and second pulley, means actuating said air clutch, whereby said friction element unites said second pulley with said hub to rotate said second pulley, said first driven shaft having a third pulley fixed thereon, drive means between said second pulley and said third pulley, an overriding cam clutch having a hub fastened to said first driven shaft, an overriding clutch element provided with a fourth pulley rotatively mounted upon said hub, drive means between said first pulley and said fourth pulley whereby said drive shaft rotates said fourth pulley, said hub and said first driven shaft, said overriding cam clutch being operative upon actuation of said friction element whereby said third pulley rotates said first driven shaft faster than the rotation imparted by said fourth pulley, a machine frame, said drive shaft and said first driven shaft being rotatably mounted in said machine frame, a first gear housing provided with a first bottom gear case fastened to said machine frame, a first stub shaft, provided with a first driven gear and a first sprocket hub having a first sprocket, rotatively mounted in said first bottom gear case and said first gear housing, a first drive gear, fastened to said first driven shaft, in driving engagement with said first driven gear, whereby said first driven shaft rotates said first sprocket, to drive said first sprocket at variable speeds.

3. A differential drive consisting of a drive shaft and a first driven shaft, means on said drive shaft for rotating said drive shaft, a first pulley fixed to said drive shaft, an overriding air clutch having a hub fixed to said drive shaft, a second pulley freely rotatable upon said drive shaft and a friction element between said hub and second pulley, means actuating said air clutch, whereby said friction element unites said second pulley with said hub to rotate said second pulley, said first driven shaft having a third pulley fixed thereon, drive means between said second pulley and said third pulley, an overriding cam clutch having a hub fastened to said first driven shaft, an overriding clutch element provided with a fourth pulley rotatively mounted upon said hub, drive means between said first pulley and said fourth pulley whereby said drive shaft rotates said fourth pulley, said hub and said first driven shaft, said overriding cam clutch being operative upon actuation of said friction element whereby said third pulley rotates said first driven shaft faster than the rotation imparted by said fourth pulley, a machine frame, said drive shaft and said first driven shaft being rotatably mounted in said machine frame, a first gear housing provided with a first bottom gear case fastened to said machine frame, a first stub shaft, provided with a first driven gear and a first sprocket hub having a first sprocket, rotatively mounted in said first bottom gear case and said first gear housing, a first drive gear, fastened to said first driven shaft, in driving engagement with said first driven gear, whereby said first driven shaft rotates said first sprocket to drive said first sprocket at variable speeds, a fifth pulley fixed to said drive shaft and an overriding air clutch having a hub fixed to said drive shaft, a sixth pulley freely rotatable upon said drive shaft and a friction element bet-ween said hub and sixth pulley, means actuating said air clutch whereby said friction element unites said sixth pulley with said hub to rotate said sixth pulley, a second driven shaft having a seventh pulley fixed thereon, drive means between said seventh pulley and said sixth pulley, an overriding cam clutch having a hub fastened to said second driven shaft, an overriding clutch element provided with an eighth pulley rotatively mounted upon said hub, drive means between said eighth pulley and said fifth pulley whereby said drive shaft rotates said eighth pulley, said hub and said second driven shaft, said overriding cam clutch being operative upon actuation of said friction element whereby said seventh pulley rotates said second driven shaft faster than the rotation imparted by said eighth pulley, a machine frame, said second driven shaft being rotatably mounted in said machine frame, a second gear housing provided with a second bottom gear case fastened to said machine frame, a second stub shaft provided with a second driven gear and a second sprocket hub having a second sprocket, rotatively mounted in said second bottom gear case and said second gear housing, a second drive gear, fastened, to said second driven shaft in driving engagement with said second driven gear, whereby said second driven shaft rotates said second sprocket to drive said second sprocket at relative varying speeds to said first sprocket.

4. A differential drive consisting of a drive shaft and a first driven shaft, means on said drive shaft for rotating said drive shaft, a first pulley fixed to said drive shaft, an overriding air clutch having a hub fixed to said drive shaft, a second pulley freely rotatable upon said drive shaft and a friction element between said hub and second pulley, means actuating said air clutch, whereby said friction ele ment unites said second pulley with said hub to rotate said second pulley, said first driven shaft having a third pulley fixed thereon, drive means between said second pulley and said third pulley, an overriding cam clutch having a hub fastened to said first driven shaft, an overriding clutch element provided with a fourth pulley rotatively mounted upon said hub, drive means between said first pulley and said fourth pulley whereby said drive shaft rotates said fourth pulley, said hub and said first driven shaft, said overriding cam clutch being operative upon actuation of said friction element whereby said third pulley rotates said first driven shaft faster than the rotation imparted by said fourth pulley; a fifth pulley fixed to said drive shaft and an overriding air clutch having a hub fixed to said drive shaft, a sixth pulley freely rotatable upon said drive shaft and a friction element between said hub and sixth pulley, means actuating said air clutch whereby said friction element unites sixth pulley with said hub to rotate said sixth pulley, a second driven shaft having a seventh pulley fixed thereon, drive means between said seventh pulley and said sixth pulley, an overriding cam clutch having a hub fastened to said second driven shaft, an overriding clutch element provided with an eighth pulley rotatively mounted upon said hub, drive means between said eighth pulley and said fifth pulley whereby said drive shaft rotates said eighth pulley, said hub and said second driven shaft, said overriding cam clutch being operative upon actuation of said friction element whereby said seventh pulley rotates said second driven shaft faster than the rotation imparted by said eighth pulley, a machine frame comprising a first stanchion, a second stanchion, a third stanchion, all parallel spaced relation, a first cross member and a second cross member, fastened to said first stanchion, said second stanchion, and said third stanchion, a first gear housing having first end caps fastened to said first cross member and to said second cross member, a first bottom gear case fastened to said first end caps, a first stub shaft rotatively mounted in said first bottom gear case and in said first gear housing, a first sprocket hub provided with a first sprocket, fastened to said first stub shaft, a first driven gear fastened to said first stub shaft, means rotatively supporting said first driven shaft on opposite ends, respectively, in said first stanchion, second stanchion, and said first end caps, a first drive gear fastened to said first driven shaft and in mesh with said first driven gear, means rotatively supporting said drive shaft on opposite ends, respectively, in said first stanchion and said third stanchion, a second gear housing having second end caps fastened to said first cross member and to said second cross member, a second bottom gear case fastened to said second end caps, a second stub shaft rotatively mounted in said second bottom gear case and in said second gear housing, a second sprocket hub provided with a second sprocket, fastened to said second stub shaft, a second driven gear fastened to said second stub shaft, means rotatively supporting said second driven shaft on opposite ends, respectively, in said second stanchion, third stanchion and said second end caps, a second drive gear fastened to said second driven shaft and in mesh with said second driven gear, whereby said drive shaft through said first pulley rotates said first sprocket and through said fifth pulley rotates said second sprocket, actuation of said first friction element rotates said first sprocket at a different relative speed to said second sprocket, and actuation of said second friction element rotates said second sprocket at a different relative speed to said first sprocket.

5. A differential drive for a tentering machine, consisting of a drive shaft and a first driven shaft, means on said drive shaft for rotating said drive shaft, a first pulley fixed to said drive shaft, an overriding clutch, having a hub fixed to said drive shaft, a second pulley freely rotatable upon said drive shaft, and a friction element between said hub and second pulley, means actuating said overriding clutch, whereby said friction element unites said second pulley with said hub to rotate said second pulley, said first driven shaft having a third pulley fixed thereon, drive means between said second pulley and said third pulley, an overriding clutch having a hub fastened to said first driven shaft, an overriding clutch element provided with a fourth pulley rotatively mounted upon said hub, drive means between said first pulley and said fourth pulley, whereby said drive shaft rotates said fourth pulley, said hub and said first driven shaft, said overriding clutch being operative upon actuation of Said friction element, whereby said third pulley rotates said first driven shaft faster than the rotation imparted by said fourth pulley, a fifth pulley fixed to said drive shaft and a second overriding clutch having a hub fixed to said drive shaft, a sixth pulley freely rotatable upon said drive shaft, and a friction element between said hub and sixth pulley, means actuating said second overriding clutch, whereby, said friction element unites said sixth pulley with said hub to rotate said sixth pulley, a second driven shaft having a seventh pulley affixed thereon, drive means between said seventh pulley and said sixth pulley, a fourth overriding clutch having a hub fastened to said second driven shaft, an overriding clutch element provided with an eighth pulley rotatively mounted upon said hub, drive means between said eighth pulley and said fifth pulley, whereby, said drive shaft rotates said eighth pulley, said hub and said second driven shaft, said fourth overriding clutch being operative upon actuation of said friction element, whereby, said seventh pulley rotates said second driven shaft faster than the rotation imparted by said eighth pulley, a tentering machine having a frame, a first shaft, provided with a first drive sprocket, rotatively mounted in said frame, a second shaft, provided with a first driven sprocket, rotatively mounted in said frame, a third shaft, provided with a second drive sprocket, rotatively mounted in said frame, a fourth shaft, provided with a second driven sprocket, rotatively mounted in said frame, a first tenter chain rotatively connected to said first drive sprocket and said first driven sprocket, a second tenter chain rotatively connected to said second driven sprocket, and first drive means rotatively connecting said first driven shaft with said first shaft, and a second drive means rotatively connecting said second driven shaft with said third shaft, to thereby, rotate said first tenter chain at a different relative speed in relation to said second tenter chain.

6. A differential drive consisting of a drive shaft and a first driven shaft, means on said drive shaft for rotating said drive shaft, a first pulley fixed to said drive shaft, an overriding air clutch having a hub fixed to said drive shaft, a second pulley fieely rotatable upon said drive shaft and a friction element between said hub and second pulley, means actuating said air clutch, whereby said friction element unites said second pulley with said hub to rotate said second pulley, said first driven shaft having a third pulley fixed thereon, drive means between said second pulley and said third pulley, an overriding carn clutch having a hub fastened to said first driven shaft, an overriding clutch element provided with a fourth pulley rotatively mounted upon said hub, drive means between said first pulley and said fourth pulley whereby said drive shaft rotates said fourth pulley, said hub and said first driven shaft, said overriding cam clutch being operative upon actuation of said friction element whereby said third pulley rotates said first driven shaft faster than the rotation imparted by said fourth pulley, a fifth pulley fixed to said drive shaft and an overriding air clutch having a hub fixed to said drive shaft, a sixth pulley freely rotatable upon said drive shaft and a friction element between said hub and sixth pulley, means actuating said air clutch whereby said friction element unites said sixth pulley with said hub to rotate said sixth pulley, a second driven shaft having a seventh pulley fixed thereon, drive means between said seventh pulley and said sixth pulley, an overriding cam clutch having a hub fastened to said second driven shaft, an overriding clutch element provided with an eighth pulley rotatively mounted upon said hub, drive means between said eighth pulley and said fifth pulley whereby said drive shaft rotates said eighth pulley, said hub and said second driven shaft, said overriding cam clutch being operative upon actuation of said friction element whereby said seventh pulley rotates said second driven shaft faster than the rotation imparted by said eighth pulley, a machine frame, said drive shaft, said first driven shaft and said second driven shaft being rotatably mounted in said machine frame, a first pair of side rails, 21 second pair of side rails, means slidably mounting said first pair of side rails and said second pair of side rails on said machine frame for movement toward and away from each other, a first overfeed device, means fastening said first overfed device to said first pair of side rails, a second overfeed device, means fastening said second overfeed device to said second pair of side rails, a first drive mechanism connecting said first overfeed device to said first driven shaft, and a second drive mechanism connecting said second overfeed device to said second driven shaft to thereby actuate said first overfeed device at a different relative speed to said second overfeed device.

References Cited UNITED STATES PATENTS 2,482,270 9/1949 Grundy 26-57 2,703,161 3/1955 Keim et al 74722 X 3,020,780 2/1962 McLerran 74-722 X 3,053,361 9/1962 Hause 192--45 X 3,087,589 4/1963 Gorsky 192--45 3,192,798 7/1965 Twamley 74-722 3,203,279 8/1965 Rahrig et a1 74722 3,256,751 6/1966 Tuck et al 192-45 X 3,295,625 1/1967 Ordorica et al 192-45 X ARTHUR T. MCKEON, Primary Examiner.

US. Cl. X.R. 74--722 

